Brocade Multi-Service IronWare Switching Configuration Guide (Supporting R05.6.00) - Manual (Page 723)

Multi-Service IronWare Switching Configuration Guide 693
53-1003036-02
PIM Over MCT
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P1 sends this to P2 via MDUP.
P2 adds (*, G1) to CCEP2 upon processing it.
R sends IGMP report for (*, G2).
Client forwards it to P2 on CCEP2.
P2 sends this to P1 via MDUP.
P1 adds (*, G2) to CCEP1 upon processing it.
Final result, both P1 and P2 has both (*, G1) and (*, G2) on their local CCEPs.
Traffic Load sharing on the CCEPs
For a stream that has a receiver behind the Client, both MCT Peers recieve the traffic, and each has
to decide whether to forward the traffic to the local CCEP or let the remote peer take care of it. The
following simple decision function is used to determine this.
• If the CCP is down, it will forward locally.
• If the remote CCEP is down, it will forward locally.
• If the local CCEP is down, it will not forward locally.
• If the ingress is the CEP, it will forward locally.
• If the ingress is the ICL, it will not forward locally.
• If the ingress is a different CCEP, it will forward locally.
Use the following expression to determine the traffic load sharing.
Forward locally =
((Src_addr + Grp_addr) & 0x00000001) ^ ((UINT32)(local_brdige_id > remote_bridge_id))
Sending IGMP Queries on CCEPs
Since there are two chassis connected to the same MCT VLAN and since the Client is not going to
flood the incoming IGMP Queries to the other chassis, both chassis could end up electing
themselves as the IGMP Querier and sending queries on the CCEPs and the hosts behind the client
will end up responding to both. To avoid this, the IGMP surpresses queries going out of the CCEP
port on one of the MCT Peers. The following algorithm is used:
If (CCP connection is down)
Send Queries on local CCEP.
Else if (remote CCEP is down)
Send Queries on local CCEP.
Else if (local CCEP is down)
Suppress Queries on local CCEP.
Else if (local-bridge-id > remote-bridge-id)
Send Queries on local CCEP.
Else
Suppress Queries on local CCEP.